Security of ProtectedObject

Question

Is ProtectedObject really secure? Otherwise, do you have any advice?

public class ProtectedBinary : IDisposable
{
    private byte[] pBArray;
    private int originPBArraySize;

    public ProtectedBinary(byte[] data)
    {
        originPBArraySize = data.Length;
        Pad(ref data);
        ProtectedMemory.Protect(data, MemoryProtectionScope.SameProcess);

        pBArray = new byte[data.Length];
        Array.ConstrainedCopy(data, 0, pBArray, 0, data.Length);
    }

    public void Get(out byte[] outArray)
    {
        ProtectedMemory.Unprotect(pBArray, MemoryProtectionScope.SameProcess);

        outArray = new byte[originPBArraySize];
        Array.Copy(pBArray, outArray, originPBArraySize);
        Unpad(ref outArray);

        ProtectedMemory.Protect(pBArray, MemoryProtectionScope.SameProcess);
    }

    public void Clear()
    {
        pBArray.Clear(); // set all bytes to 0x00
        originPBArraySize = 0;
    }

    public void Dispose()
    {
        Clear();
    }

    private void Pad(ref byte[] bytes)
    {
        Array.Resize(ref bytes, 16 * ((bytes.Length + 15) / 16));
    }

    private void Unpad(ref byte[] bytes)
    {
        Array.Resize(ref bytes, originPBArraySize);
    }
}

public class ProtectedObject<T> : IDisposable
{
    private ProtectedBinary pBin;

    private bool isDisposed;

    public ProtectedObject(T obj)
    {
        byte[] serializedObject = ULBinConvert.Serialize(obj);
        pBin = new ProtectedBinary(serializedObject);
    }

    public void Get(out T obj)
    {
        if (isDisposed)
            throw new ObjectDisposedException("Protected object is disposed");
        byte[] serializedObject;
        pBin.Get(out serializedObject);
        obj = ULBinConvert.Deserialize<T>(serializedObject);
        serializedObject.Clear();
    }

    public void Dispose()
    {
        if (!isDisposed)
        {
            pBin.Dispose();
            isDisposed = true;
        }
    }
}

security.stackexchange.com/questions/29748/dpapi-and-malware might hold some answers for you about ProtectedMemory. — James Snell
– James Snell, Commented Oct 23, 2014 at 18:27
@Dmitry If anyone would have memory dump, can he find out what was stored in ProtectedObjects? — Artem Sokolov
– Artem Sokolov, Commented Oct 24, 2014 at 3:48

Nick Udell · Accepted Answer · 2014-10-30 11:11:52Z

Most of it looks fine to me, but why do you have void methods with out parameters? This makes no sense to me, and only serves to make usage more awkward. As such I would recommend:

public T Get()
{
    if (isDisposed)
        throw new ObjectDisposedException("Protected object is disposed");
    byte[] serializedObject = pBin.Get();
    T result = ULBinConvert.Deserialize<T>(serializedObject);
    serializedObject.Clear();
    return result;
}

Secondly, I don't like a lot of your variable names. You're not paying by the character, so there's no real benefit in shortening them at the cost of making it a slower read. pBin is significantly less readable than protectedBinary

You should also refrain from putting things like array into the variable name unless there is no better way to describe the variable. Most of the time it is unnecessary, as it is in pBArray or outArray.

Stack Exchange Network

Security of ProtectedObject

1 Answer 1

You must log in to answer this question.

Hot Network Questions

Security of ProtectedObject

1 Answer 1

You must log in to answer this question.

Related

Hot Network Questions